The invention relates to improvements in hinge joints of the class disclosed in the commonly owned U.S. Pat. No. 4,563,039 whose disclosure is incorporated herein by reference. More particularly, the invention relates to improvements in hinge joints which can be used in motor vehicles to adjustable connect a mobile (second) component (such as the back of a seat in a motor vehicle) with a stationary (first) component (such as the bottom part of the seat).
Commonly owned Geram Offenlegungsschrift No. 27 57 907 discloses a hinge joint wherein the means for movably connecting the second component of an adjustable seat to a stationary first component comprises a shaft which is surrounded by a C-shaped eccentric for the second component, and such eccentric is biased radially outwardly so as to increase the eccentricity of a (second) gear which is provided on the second component and must roll along a (first) gear on the first component when the second component is to be adjusted by changing its angular position with reference to the first component. The shaft is formed with two flats for complementary internal surfaces on the legs of the eccentric to ensure that the shaft and the eccentric can be rotated as a unit by means of a hand wheel or the like. The means for biasing the eccentric relative to the shaft can comprise a cushion or pad of elastomeric material, a package of dished springs or the like. The purpose of the biasing means is to urge the second gear radially into mesh with the first gear and to thus eliminate the possibility of radial wobbling irrespective of eventual machining tolerances and/or unavoidable play between the mating teeth of the two gears. This applies for the stage during which the second component is moved relative to the first component as well as for the stage or phase of idleness of the hinge joint, i.e., while the second component is held in a selected angular position. The biasing means must be installed under a certain initial stress in order to reliably prevent any stray movements, especially while the second component is held in a selected angular position. Such initial stressing of the biasing means necessitates the application of a reasonably large force when the occupant of the seat or another person desires to change the inclination of the back of the seat in a motor vehicle.